The Maternal Lifestyle Study (MLS) was the largest of the NIH longitudinal studies of children with prenatal cocaine exposure (PCE). MLS was a longitudinal multi-site observational study of the long-term effects of in-utero exposure to cocaine on child development. MLS was conducted at four geographically diverse, collaborating university centers (Wayne State University, University of Tennessee at Memphis, University of Miami, and Brown University). Participants were identified during the newborn period while in the hospital. The MLS began enrollment of a longitudinal birth cohort of 1,388 infant/mother dyads in 1993. Subjects in the follow-up were seen from 1 month of age through 16 years of age. The overall purpose of the study was to investigate the effects of drug use during pregnancy on acute neonatal events and long-term physical health, social, behavioral and neurodevelopmental outcomes.

The study included five phases of data collection. The first phase examined acute effects of maternal substance use on infant health outcomes at birth. The four subsequent follow-up phases examined development across the following periods: Phase II -- 1-36 months; Phase III -- 4-7 years; Phase IV -- 8-11 years; Phase V -- 12-16 years. In Phase I, the study screened 19,079 infants between May 1993 and May 1995. Mothers at these centers were enrolled in the study within 24 hours after delivery. Initial screening included the mother's labor and delivery chart, the newborn admission chart, and a meconium sample. Infant meconium was collected and samples were express shipped to a central laboratory for analysis of metabolites of illicit drugs. Additionally, a drug use questionnaire that addressed the mother's use during pregnancy of nicotine, alcohol, marijuana, cocaine, opiates, and other illicit drugs was given by research staff that were trained and certified in the reliable administration of all of the study interviews. A mother-child dyad was considered exposed if a mother admitted to using cocaine during pregnancy and/or there was a positive meconium assay for cocaine metabolites including gas chromatography/mass spectrometry confirmation. Nonexposed children were those who were born to mothers who denied cocaine use, confirmed by negative meconium test results. Acute outcomes evaluated in Phase I included: central nervous system (CNS) and autonomic nervous system (ANS) findings and symptoms, abruption placenta, fetal growth retardation, congenital malformations, respiratory distress syndrome, chronic lung disease, intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, and periventricular leukomalacia.

From the initial Phase I cohort of 8,627 dyads, 1,388 participants for the longitudinal follow-up were recruited at a 1-month visit. The sample included a cohort of exposed infants (n = 658) who were group matched within site with a group of non-exposed comparison infants (n=730) by gestational age categories (32, 33-36, and 36 weeks) and child gender, race, and ethnicity. At the 1-month visit, the biological mother was interviewed for a detailed inventory of her legal and illegal drug use during pregnancy using the Maternal Interview of Substance Use (MISU). Phase II examined the first 36 months of life for the sample of 1,388. Follow-up visits occurred at 1, 4, 7, 9, 12, 18, 24, and 36 months (corrected age). Outcomes examined included physical health, developmental, behavioral, social, and environmental outcomes. Phase III followed children at 4, 4.5, 5, 6, and 7 years. In addition to outcomes examined in Phase II, school performance and neurodevelopmental measures of emotional and behavioral self-regulation were also examined. Phase IV covers ages 8, 9, 10, and 11 years of age. Outcomes in this phase were further expanded to include antisocial behavior, onset of substance use, psychopathology, and neuroendocrine function. Phase V assessed children at ages 12, 13, 14, 15, and 16 years of age. The fifth phase of the study has a significant emphasis on psychopathology, school performance, peer relationships, substance use onset and risk taking behaviors, including risky sexual behaviors.

United States Department of Health and Human Services. National Institutes of Health. Eunice Kennedy Shriver National Institute of Child Health and Human Development (U10-HD-27904, U10-HD-21385, U10-HD-21415, U10-HD-21397, U10-HD-36790, U01-HD-36790, U01-HD-19897, N01-HD-2-3159),
United States Department of Health and Human Services. National Institutes of Health. National Institute on Drug Abuse (U10-DA-024119, U10-DA-024117, U10-DA-024118, U10-DA-024128),
United States Department of Health and Human Services. National Institutes of Health. National Institute of Mental Health,
United States Department of Health and Human Services. Administration for Children and Families. Administration on Children, Youth and Families,
United States Department of Health and Human Services. Substance Abuse and Mental Health Services Administration.
Center for Substance Abuse Treatment

Access to the MLS data is restricted. Users interested in obtaining these data must complete a Restricted Data Use Agreement, specify the reasons for the request, and obtain IRB approval or notice of exemption for their research. Apply for access to these data through the ICPSR data access request system portal.

MLS was conducted under the auspices of the National Institute on Drug Abuse (NIDA) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), with co-funding from the National Institute of Mental Health (NIMH), Administration on Children, Youth, and Families (ACYF), and the Center for Substance Abuse Treatment (CSAT).

The Maternal Lifestyle Study (MLS) enrolled 8,627 mothers shortly after birth from four geographically-diverse sites. Mothers provided informed consent, and a NIDA Certificate of Confidentiality was obtained by each site that assured confidentiality of information regarding the mothers' drug use. The recruitment strategy was designed to identify and recruit all women delivering very low birth weight infants of 501 to 1,500 grams. For mothers delivering low birth weight infants (1,501-2,500 grams) and normal birth weight infants (greater than 2,500 grams), recruitment varied by site. Exclusion criteria have been published.

The longitudinal follow-up was recruited from the original large sample. Exposed dyads were group matched within site to non-exposed dyads on race, infant gender and gestational age (less than 32 weeks, 33-36 weeks, and greater than 36 weeks). There were 1,388 dyads enrolled in the longitudinal sample at the 1-month visit, including 658 exposed (543 infants with prenatal cocaine exposed; 58 with opiate exposure; and 57 with both cocaine and opiate exposure) and 730 comparison dyads who were not exposed to either cocaine or opiates during pregnancy. To be included, the dyad had to participate in the 1-month visit (age corrected for prematurity). Potential matched comparison dyads not attending the 1-month visit could be replaced, but not exposed dyads, leading to uneven size groups.

2016-03-31 The ninth release of MLS is an update that included the addition of scoring variables to some datasets and confidentiality changes. Also, improvements were made to questionnaire and codebook covers.

2016-03-29 The eighth release of MLS includes data and documentation for years 13 through 16 from Phase V. These data are included in parts 172-203.

2016-02-02 The seventh release of MLS includes data and documentation for year 11 from Phase IV and year 12 from Phase V. These data are included in parts 154-171.

2015-12-21 The sixth release of MLS includes data and documentation for years 9 and 10 from Phase IV. These data are included in parts 136-153.

2015-12-08 The fifth release of MLS includes data and documentation for years 5.5, 6 and 7 from Phase III and year 8 from Phase IV. These data are included in parts 103-135.

2015-08-24 The fourth release of MLS includes data and documentation for years 4.5 and 5 from Phase III. These data are included in parts 84-102. The study level documentation for this study has been updated to include additional information about file merging performed by NAHDAP. Previously released data is not being updated in this release.

2015-08-10 The third release of the MLS study includes data and documentation for year 4 from Phase III. This portion of the study is contained in parts 73-83. The study level documentation for this study has been updated to include additional information about file merging performed by NAHDAP. Previously released data is not being updated in this release.

2014-05-19 The second release of the MLS study includes data and documentation for months 18-36 from Phase II. The study level documentation for this study has been updated to include additional information about file merging performed by NAHDAP. Previously released data is not being updated in this release.

2014-04-01 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

Created variable labels and/or value labels.

Standardized missing values.

Performed recodes and/or calculated derived variables.

Checked for undocumented or out-of-range codes.

Notes

The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.

One or more files in this data collection have special restrictions. Restricted data files are not available for direct download from the website; click on the Restricted Data button to learn more.

The citation of this study may have changed due to the new version control system that has been implemented. Please see version history for more details.